When adding an empty additional-binding extension to a binding element the validator does not report the missing mandatory elements #544
Description
Consider the following (empty) additional binding extension:
<binding>
<extension url="http://hl7.org/fhir/tools/StructureDefinition/additional-binding"/>
<strength value="preferred"/>
</binding>
The legacy validator reports the 2 required missing fields:
Message : Instance count for 'Extension.extension:purpose' is 0, which is not within the specified cardinality of 1..1
Context : StructureDefinition.differential[0].element[0].binding[0].extension[0]
Message : Instance count for 'Extension.extension:valueSet' is 0, which is not within the specified cardinality of 1..1
Context : StructureDefinition.differential[0].element[0].binding[0].extension[0]
However the Firely validator does not.
When the additional binding extension is not empty then the Firely validator does report the 2 required fields.
<binding>
<extension url="http://hl7.org/fhir/tools/StructureDefinition/additional-binding">
<extension url="documentation">
<valueMarkdown value="Test"/>
</extension>
</extension>
<strength value="preferred"/>
</binding>
Message : Instance count is 0, which is not within the specified cardinality of 1..1 (for slice purpose)
Context : StructureDefinition.differential[0].element[0].binding[0].extension[0].extension
Message : Instance count is 0, which is not within the specified cardinality of 1..1 (for slice valueSet)
Context : StructureDefinition.differential[0].element[0].binding[0].extension[0].extension
This issue may apply in general to extensions with mandatory fields but I have not checked that.